Visualization research and interaction research have been connected for some time, and there's a growing trend toward integrating the two. Four examples illustrate the potential and challenges of this integration: 3D selection techniques in brain visualizations, interactive multiview scientific visualizations, fluid pen- and touch-based interfaces for visualization, and modeling human performance in interactive visualization-related tasks. Three goals (improving accuracy, linking multiple visualization strategies, and making data analysis more "fluid") serve as a guide for future interactive-visualization research targeted at improving visualization tools' impact on scientific workflows.